The Impact of Geological Structures on Groundwater Potential Assessment in Volcanic Rocks of the Northwestern Ethiopian Plateau: A Review

Abstract. This review examines the influence of geological structures on groundwater potential in the volcanic rocks of the Northwestern Ethiopian Plateau. The region's tectonic complexity has shaped fractures, faults, and other features that significantly impact groundwater storage and flow. Geological structures, including faults, fractures, folds, and lineaments, play a crucial role in groundwater dynamics, particularly in terrains with limited primary porosity, where secondary porosity dominates aquifer characteristics. Faults can act as conduits or barriers, controlling recharge, flow, and discharge based on their structural properties and interaction with surrounding rocks. Fractures create secondary porosity, enabling groundwater storage and movement in otherwise impermeable rocks. Lineaments, representing subsurface features such as faults and lithological boundaries, are key indicators of groundwater potential, especially in hard-rock and volcanic terrains. Additionally, folding influences aquifer configuration and flow by creating confined or unconfined groundwater systems through anticlines, synclines, and other structures. The review underscores the importance of integrating geological, geophysical, and hydrological methods for effective groundwater exploration and management. Volcanic terrains present unique challenges due to their complex lithology and structural heterogeneity. Case studies from various volcanic settings demonstrate how structural features enhance or restrict groundwater movement and highlight the interplay between volcanic lithology and tectonic processes. Recommendations are provided for using a multidisciplinary approach to address these challenges and ensure sustainable groundwater resource management in volcanic regions.